#!/usr/bin/env node

const http = require('http'),
      qs   = require('querystring'),
      fs   = require('fs'),
      log  = console.log;

let html = fs.readFileSync('./12-todo.html').toString('utf8');

let items  = [],
    result = {
      status: 200,
      reason: 'ok',
    };

http.createServer((req,res) => {
  logRequest(req);

  if(req.url.slice(0,5) !== '/todo'){
    if(req.url === '/'){
      res.end(html);
    }else if(req.url == '/12-todo.js'){
      fs.createReadStream('./12-todo.js').pipe(res);
    }else{
      res.end('not api request!');
    }
    return;
  }


  switch(req.method){
    case 'GET':
      select(req,res);
    break;

    case 'POST':
      insert(req,res);
    break;

    case 'PUT':
      update(req,res);
    break;

    case 'DELETE':
      remove(req,res);
    break;

    default:
      res.end(`${req.method} method not support`);
    break;
  }
}).listen(8080);

function logRequest(req){
  log(`${req.method} ${req.url} HTTP/${req.httpVersion}`);
  log(req.headers);
  log();
}

function select(req,res){
  result.data = items;
  res.end(JSON.stringify(result));
}

function insert(req,res){
  let data = '';
  req.on('data',(chunk) => data += chunk);
  req.on('end',() => {
    let item = qs.parse(data).item;

    if(item !== '' && typeof item !== undefined){
      items.push(item);
      res.end(JSON.stringify(result));
    }else{
      result.status = 401;
      result.reason = 'item is empty';
      res.end(result);
    }
  });
}

function update(req,res){
  let id = req.url.split(':')[1];

  let data = '';
  req.on('data', chunk => data += chunk);
  req.on('end', () => {
    let item = qs.parse(data).item;
    if(item !== '' && typeof item !== 'undefined'){
      items[id] = item;
      res.end(JSON.stringify(result));
    }else{
      result.status = 402;
      result.reason =  'item is empty';
      res.end(JSON.stringify(result));
    }
  });

}

function remove(req,res){
  let id = req.url.split(':')[1];

  if(typeof id === 'undefined'){
    items=[];
    result.status = 200;
    result.reason = 'delete all success';
    res.end(JSON.stringify(result));
    return;
  }
  items = items.splice(id,1);
  result.status = 200;
  result.reason = 'delete success';
  res.end(JSON.stringify(result));
}

